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Are the Antioxidant, Antibacterial, and Cancer Fighting Properties of CBD All They’re Cracked Up to Be?

Written by Nick Congleton

Since the Farm Bill was passed in 2018, there’s been an explosion of research into the properties and potential effects of cannabidiol (CBD). While the results generally trend in a promising direction, there are contradictory studies causing some concern.

One group of researchers decided to tackle the contradictory library of research surrounding CBD to see whether they could corroborate one side or the other. [1] So, they tested CBD’s abilities as an antioxidant, antibacterial, and its capability to fight cancer. They also included cannabidivarin (CBDV), a less studied analog of CBD. It’s something of an understatement to say that their results were less than fantastic for CBD.


CBD as an Antioxidant

In the study, the researchers looked to see how effective CBD and CBDV were at scavenging the common free radicals, ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl), thereby preventing them from harming healthy cells. The study compared each cannabinoid’s ability to scavenge the free radicals against, Trolox, a chemical antioxidant similar to vitamin E.

The Trolox significantly outperformed both cannabinoids in the test. In fact, the cannabinoids were 90% less effective than Trolox in scavenging DPPH. So, at least as ABTS and DPPH are concerned, CBD and CBDV don’t appear to have significant antioxidant properties. Other studies, however, have confirmed CBD’s antioxidant capabilities. [2, and other studies therein]


CBD as an Antibacterial

To test the antibacterial properties of CBD and CBDV, the researchers exposed two infectious bacteria strains, Escherichia coli and Staphylococcus aureus (the bacterium responsible for Staph infections), to different concentrations of the cannabinoids for various periods of time. What they found was only slightly more encouraging than the antioxidant tests.

Neither cannabinoid impacted E. coli. When it came to Staphylococcus, they did find a measurable antimicrobial effect, with CBD being more effective at killing the bacteria. Again, other studies have demonstrated much stronger antibacterial activities correlated to CBD. [3]


CBD for Fighting Cancer

CBD’s purported cancer-fighting abilities have been known for quite some time, but it hasn’t been studied nearly as extensively as conventional cancer treatments.  The researchers conducting the study chose a range of cancerous human cells as well as healthy ones to compare the effects, if any, of CBD.

They found that CBD was, in fact, cytotoxic, meaning harmful to cells. Interestingly, it wasn’t only harmful to the cancerous cells and caused harm to the healthy cells as well, contradicting previous research. CBD and CBDV both altered metabolism in the mitochondria of the cells. In some of the cancer cells, this led to greater destabilization and cell death.

The researchers also studied the impact of CBD and CBDV on DNA replication. They found that both cannabinoids inhibited DNA replication and caused DNA damage in both healthy and cancerous cells.

The researchers did find one major difference between the effects on cancerous and healthy cells. In cancerous cells, cell membranes were significantly weakened by CBD and CBDV, while in the healthy cells, the membranes remained unchanged.

Clearly, CBD does show some promise in fighting cancer, but like many other conventional cancer treatments, this study postulated that CBD may also toxic to healthy cells. The conclusions of this study regarding CBD and anticancer properties differ from other research papers. [4-7]

Altogether, the findings of this study paint a less helpful picture of CBD with the cannabinoid edging into “harmful” territory in some instances. According to the researchers, more research needs to be done to get a clearer overall picture of CBD and its interactions with the body. This is especially true since the findings of this particular study contract with several other studies in the scientific literature.




[1] Russo C, Lavorgna M, Nugnes R, Orlo E, Isidori M. Comparative assessment of antimicrobial, antiradical and cytotoxic activities of cannabidiol and its propyl analogue cannabidivarin. Sci Rep. 2021;11(1):22494. [journal impact factor = 4.380; times cited = 0]


[2] Atalay S, Jarocka-Karpowicz I, Skrzydlewska E. Antioxidative and anti-inflammatory properties of cannabidiol. Antioxidants (Basel). 2019;9(1):21. [journal impact factor = 5.952; times cited = 128]


[3] Blaskovich MAT, Kavanagh AM, Elliott AG, et al. The antimicrobial potential of cannabidiol. Commun Biol. 2021;4(1):7. [journal impact factor = 6.268; times cited = 17]


[4] Marcu JP, Christian RT, Lau D, et al. Cannabidiol enhances the inhibitory effects of delta9-tetrahydrocannabinol on human glioblastoma cell proliferation and survival. Mol Cancer Ther. 2010;9(1):180-189. [journal impact factor = 6.261; times cited = 117]


[5] Elbaz M, Nasser MW, Ravi J, et al. Modulation of the tumor microenvironment and inhibition of EGF/EGFR pathway: novel anti-tumor mechanisms of Cannabidiol in breast cancer. Mol Oncol. 2015;9(4):906-919. [journal impact factor = 6.603; times cited = 106]


[6] Volmar MNM, Cheng J, Alenezi H, et al. Cannabidiol converts NF-κB into a tumor suppressor in glioblastoma with defined antioxidative properties. Neuro Oncol. 2021;23(11):1898-1910. [journal impact factor = 12.300; times cited = 3]


[7] Hamad H, Olsen BB. Cannabidiol induces cell death in human lung cancer cells and cancer stem cells. Pharmaceuticals (Basel). 2021;14(11):1169. [journal impact factor = 5.677; times cited = 0]

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Nick Congleton

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